Veteran FBI agents say FBI Director James Comey has permanently damaged the bureau’s reputation for uncompromising investigations with his “cowardly” whitewash of former Secretary of State Hillary Clinton’s mishandling of classified information using an unauthorized private email server.

Feeling the heat from congressional critics, Comey last week argued that the case was investigated by career FBI agents, “So if I blew it, they blew it, too.”

But agents say Comey tied investigators’ hands by agreeing to unheard-of ground rules and other demands by the lawyers for Clinton and her aides that limited their investigation.

“In my 25 years with the bureau, I never had any ground rules in my interviews,” said retired agent Dennis V. Hughes, the first chief of the FBI’s computer investigations unit.

Instead of going to prosecutors and insisting on using grand jury leverage to compel testimony and seize evidence, Comey allowed immunity for several key witnesses, including potential targets.